代码：<pre><code>
//*
*
根据自己写入沙盒的plist文件来判断是第几次加载，
如果是第一次加载那么就进入引导视图，
否则进入主界面
*
*/

NSString *path = [NSHomeDirectory()stringByAppendingPathComponent:@"Documents/dic.plist"];

//读取本地的字典
NSDictionary *isFirstDic = [NSDictionary dictionaryWithContentsOfFile:path];

BOOL notFirst = [[isFirstDic objectForKey:@"notFirst"]boolValue];//第一次返回的是NO

if (notFirst) {
    
     //不是第一次则直接进入到主界面
    LauchViewController *launchVC = [[LauchViewController alloc] init];
    
    _window.rootViewController = launchVC;
    
 } else {
    
    //进入导航界面
     GuideViewController *guideVC = [[GuideViewController alloc] init];
     
     _window.rootViewController = guideVC;
     
     NSMutableDictionary *dic = [NSMutableDictionary dictionary];
     
     [dic setObject:@"YES" forKey:@"notFirst"];
     
     [dic writeToFile:path atomically:YES];
    
}